Step 3: Roll the dough flat
Using a metal spoon dig chunks out of the storage container and work them in your palms a bit until they warm up enough to feel like clay. Take clay-like chunk and work it into a pancake shape. Make several handful-sized balls into pancakes and stack them, then squish the whole stack together by pushing down on it. This process is both warming the dough and making it homogeneous, attempting to work out any air bubbles between chunks.
Pull combined dough into a sphere, compressing it into the center as you work with it. Once you have a nice ball, begin flattening it with your hands. Alternate squishing downwards and pinching the edges in to prevent cracks at the circumference. Flip the dough and add more flour to the work surface as often as you need to to prevent sticking. Gradually work the dough into a rectangle shape by pushing and pulling it as you squish. Flattening with your hands this way instead of using a roller provides more control over the shape the dough forms.
Once the hand-flattened rectangle is about .75 inches thick, move it onto baking parchment and get your rolling pin. Flatten to a height of .5 inches with the roller, attempting to maintain the rectangular shape as much as possible as you do so. Once baked the dough will be cut into 2" tiles, so the final unbaked dough rectangle should measure an odd number of inches to allow .5" of clearance around the edges during the cutting process. Measure and cut off the excess dough to make an odd-number-of-inches by odd-number-of-inches rectangle and throw the scraps back into the dough pool.
Use the parchment paper to pull the dough gently onto a lip-less cookie sheet without deforming it. Because the dough is being baked in big sheets, the parchment paper is vital for being able to get it on an off the cookie sheet without cracking or bending the product.